The prior art vise mechanisms used on tables of machine tools have been provided with mechanism for rapidly advancing one vise jaw toward the other until a clamping operation is reached, at which time the jaws are closed with means providing greater leverage for clamping and whereby the jaws may be separated or retracted from each other at a greater rate than the final clamping rate.
Such prior art vises have, however, not been provided with means for precisely limiting torque applied through screwthreaded means to the moveable jaw of the vise so as to precisely limit loading of the jaws against a part therebetween and to thereby limiting precisely the amount of deflection of the jaws which will provide for precision repeat operations during the successive machining of several precision parts.